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asm question

Sorry for all these asm questions, I just learned of a method in assembly language where you can print strings to the display by moveing them byte by byte into video memory at location 0B800h, I am learning this at http://www.xs4all.nl/~smit/asm02001.htm

It mentions 80x25 text mode, and in that mode, 4000 bytes of video memory at location B800:0000 can be used, I wrote my own program afterreading the example. If i start MS-DOS and move to the directory where my program resides, and I assemble and link with TASM and TLINK. No problems assembling or linking, I then type the name of the program and hit enter, it prints a blank line to the screen. So I figured maybe B800 is the wrong memory location, I pondered and played with my code for about a hour, still blank lines, I then tryed to asemble their example, and still blank lines, I I went back to the tutorial, I read about the video mode and figured maybe dos dont use that mode, then for some strange reason I decided to open windows explorer, and find my program and double click it, WOW it worked! so it must be something to do with the video mode, I then found theis site http://www.geocities.com/SiliconVall...odeSelect.html

I read the entire page, it apears there are difernt video modes, and i was useing 80x24 text mode.

My question is how come my program will work by double clicking the Icon, yet if I try to launch it from DOS all i get is a blank line???

In snatches, they learn something of the wisdom
which is of good, and more of the mere knowledge which is of evil. But must I know what must not come, for I shale become those of knowledgedome. Peace~

Thank you for the link, I will check it out, however I am still going to learn 16 bit first before 32bit, as this is what I did with C, I learned how to make Dos apps in C, then moved on to makeing Win32 aps. So much to learn in so little time. I will soon learn how to incorporate asm code in C, so that I can write parts of my code in C, and parts in asm. As my goal is to make an operating system from scratch. 10X for the sugestions, I will definately check that link out soon.

In snatches, they learn something of the wisdom
which is of good, and more of the mere knowledge which is of evil. But must I know what must not come, for I shale become those of knowledgedome. Peace~

Sorry for the digression, but have you taken an OS class? Writing an operating system sounds a lot easier that it is. Setting up all the processes to work properly's quite a bit of work. I had dreams of writing an OS for a research project my freshman year of college (I was bored and my professors saw potential in me), but gave up after talking with the OS instructor. I ended up making a compiler instead, which was still challenging, but dramatically more easier, plus, I had the opportunity to play around with some assembly for that as well. If you want to incorporate assembly in C or C++, I suggest you start small... don't aim for an OS on your first try... I don't think you'll be happy with the results.

A DOS session is controlled by a PIF ie.DOSPRMPT.PIF etc.
This is accessible by right clicking on a dos executable
or its icon.

I suspect that there is some difference in the PIF
for your dos prompt compared to the one for
double clicking the dos executable The PIF controls
several parameters of the dos session, such as
whether it runs full screen or windowed, and whether
the dos session closes when the program terminates,
memory usage etc. etc.

Play with these settings and you will uncover the
mystery of why the program works in one circumstance
and not the other.

rcgreen, thanks so much for that info, it helps alot. Just the kind of info I was looking for. I have got a lot of learning to do. Yes I agree that OS development is a big chalenge, I have however programed in many difernt high level languages such as C, C++, a bit of python and some qbasic. I am egar to get heavy into the deeprer aspects of programing. I have been learning a lot of asm though the past week or so. Development will not start for at least another 2 or more years, as I have much to learn. However I will not give up

thanks for all your advice and suport.

In snatches, they learn something of the wisdom
which is of good, and more of the mere knowledge which is of evil. But must I know what must not come, for I shale become those of knowledgedome. Peace~